Method and means for reducing the size of tennis balls and holding the same while reduced



J. R, GAMMETER METHOD AND MEANS FOR REDUCING THE SIZE OF TENNIS BALLS AND HOLDING THE SAME WHILE REDUCED Filed April 19, 1928 June 23, 1931.

Patented June 23,1931

UNITED STATES PATENT OFFICE JOHN R. GAMMETER, OF AKRON, OHIO, ASSIGNOR TO A. G. SPALDING & BROS, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY METHOD AND MEANS FOR REDUCING THE SIZE OF TENNIS BALLS AND HOLDING THE SAME WHILE REDUCED Application filed April 19, 1928. Serial No. 271,312.

This invention relates to tennis, or similar,

4 balls having a wall of highly elastic material occur in tennis balls in the period between their manufacture and use, so that at the time they are to be put into play, they do not conform to the established, or desired, requirements, and their wall structure has become deleteriously aflected.

These undesirable results I believe to be due primarily to the expansion of the ball, or stretching ofits wall structure, under the pressure of its inflating medium, and my invention aims primarily not only to prevent any expansion of the ball beyond its normal size under external atmospheric pressure at the time of its manufacture, but to place the ball under a mechanical external pressure above that of the atmosphere, so that it will be held slightly below its normal size, as aforesaid.

To this end, my invention comprises a unique marketable article comprising a tennis, or similar, ball having a highly elastic wall and containing a fluid inflating medium under superatmospheric pressure, and a removable pellicular coating tightly embracing the surface of the ball and preferably exerting such compression thereupon that the ball will be held below its normal size at atmospheric pressure at the time of its manu facture, and the method of forming this article.

The invention also preferably comprises the employment of a coating which is substantially impervious to air, so as to avoid, or materially reduce, the oxidizing, or other deleterious effect of the external atmosphere upon the wall structure of the ball, the employment of a non-adhesive coating which can readily be peeled from the ball when it is desired to put it into play, the employment of a coating of transparent, or translucent, material for permitting observation of the surface of the ball and the reading of any inscription which may appear thereon, the employment of a coloring pigment in the coating for enhancing the attractiveness of the article, or for other purposes, and it also includes certain additional minor features which will appear from the detailed description which follows.

The invention is illustrated in the accompanying drawings, wherein:

Fig. 1 is a middle section of a tennis ball and a covering member thereon produced in accordance with my invention in its preferred form.

Fig. 2 is a similar view of a modification.

Fig. 3 is an elevation of another modification.

Fig. 4 is an elevation of still another modification.

Referring to the drawings, the ball is designated 10 in each of the figures. The covering or jacket preferabl is formed, as shown in Fig. 1, of two hemispherical shells ll, 12 of viscose, which are mounted upon the ball and overlap one upon the other in a circumferential seam 13 while they are maintained in a green weldable or unshrunk condition. The shells need not be of such small size as to fit the ball ver tightly at this stage, but I prefer that they fit snugly enough to avoid the pocketing of any substantial quantity of air between the ball and the jacket.

The jacket is then permitted to dry, which causes it to shrink and thereby to constrict and reduce the size of the ball. The compression of the ball is effected almost entirely by the mechanical contact of the jacket with the ball, if the shells are initially fitted thereto with suflicient snugness to exclude substantially all air from between them and the ball. The size of the assembly before the shrinking of the cover is indicated by the dotted line in Fig. 1.

At the end of the drying operation, the jacket is hard, substantialy inelastic and air proof, so that it holds the wall of the ball matter may be employed in the viscose for ornamental or other purposes.

The ed es ofthe shells preferably are suitably beveled in the formation thereof to provide a bevel seam, as shown at 13, giving uniform wall thickness and thus avoiding such unequal shrinkage as would hold the ball out of a spherical condition and avoiding unevenness of the inner surface of the jacket such as would cause indentation of the ball in the case of a simple lapped, non-bevel seam.

When it is desired to use the ball the jacket may be readily removed, a simple and effective expedient for that purpose being 1 to bounce the jacketed ball on a hard surface with sufficient force to rupture the jacket, which permits it to be easily removed from the ball, by further tearing if necesf; the modification shown in Fig. 2 the jacket comprises a single bag 14 of viscose which is initially formed with a cylindrical body and open-end portion, as indicated by the dotted lines in Fig. 2, and with a hemispherical bottom to fit the ball. The ball is dropped into the bag while the latter is in a green condition, a shield member 15 of suitable material such as cardboard or celluloid, shaped or deformable to fit theball and preferably beveled at its edge as shown at 16, is placed upon the ball at the middle of the uncontacted portion thereof as shown, and the bag is closed upon the ball and the shield member by gathering and tightly twisting the neck of the bag. In the case of a shrunk-on jacket,'the drying of the bag causes the twisted neck to set in its twisted condition before the bag has so shrunk as to constrict the ball very tightly, further shrinkage of the'bag then providing the desired compression of the ball.

The 'shield member 15 prevents excessive deformation of the ball y the wrinkling and unequal constricting effect of the twisted neck portion of the bag and the beveling of its edge avoids an abrupt ledge on the inner face of the constricting-structure.

In the modification shown in Fig. 3 a jacket 17 is employed which initially has the form of a flat sheet of viscose, as indicated in dotted lines, this sheet being rolled into the form of a cylindrical tube upon the ball and both ends of the tube are twisted, over respective shield members in enclosing th ball.

In Fig. 4 a ha and a shield member similar to those of ig. 2 are emplo ed and the neck of the bag is closed by simp y gathering it and clamping or securlng it in gathered condition, as by means of a wire 18 tightly wound or crimped about it. Simllar clamping means may be employed, if found necessary or desirable, for holding the neck of the bag in Fig. 2 or Fig. 3 in twisted condition.

In order to avoid brittleness when the jacket is composed of viscose, the viscose may be soaked, preferably for about an hour in a ten per cent solution of glycerine in water, so that it will be relatively pliable when dry.

It may be desirable, in order to augment the shrinkage of the jacket on the ball, to apply an external air pressure of preferably about five pounds to the square inch, to the exterior of the assembly while the jacket is drying, which will assist the jacket in compressing the ball and result in a large amount of shrinkage. Y

My invention provides the several advantages set out in the above statement of objects and as it may be variously modified without sacrifice of all such advantages I do not Wholly limit my claims to the exact form of the invention which is herein illustrated and described.

I claim:

1. A tennis, or similar, ball having a wall of elastic material and an inflating medium therein under superatmospheric pressure, said wall being constructed to conform to prescribed size and rebound requirements, and a pellieular coating substantially impervious to air shrunk upon the ball for holding it under compression and within the aforesaid prescribed size.

2. A tennis, or similar, ball having a wall of elastic material and an inflating medium therein under superatmospheric pressure, and a transparent pellieular coating substantially impervious to air shrunk upon andtightly embracing the surface of the ballfor holding it under external compression.

3. A method of preserving a tennis, or similar, ball, having an elastic wall and containing an inflatable medium under superatmospheric pressure, which consists in snugly applying to the surface thereof a pellicular coating while in an undried or unset condition, said coating being formed of a material having the property of shrinking in the drying or setting of the same, and then permitting the coating to set or shrink, whereby it will exert a contractive force upon the surface of the ball, substantially as described.

4. A tennis, or similar, ball having an elastic wall structure and having therein an inflatable medium under su eratmospheric pressure and a removable peilicular coating substantially imperviousto air and non-adhesive to the surface of the ball shrunk upon and tightly embracing the same for holding it under external compression, substantially as described.

' 5. A play ball having an elastic wall and containing an inflating medium terding to distend the ball, and a pellicular coating conforming to the entire surface of the ball and preventing the stretching of the wall by said inflating medium.

6. A tennis ball having an elastic wall and containing an inflating medium, and a viscos e coating closely conforming to the surface of the ball for holding it by compression below its maximum playing size.

7. A tennis ball having a pellicular transparent non-adhesive and removable coating snugly fitting the same for holding it agamst distension.

In testimony whereof I afiix my signature.

JOHN R. GAMMETER. 

